CN117396673A - Wind turbine with a nacelle having an offset centre of gravity - Google Patents

Abstract

A wind turbine includes a tower, a nacelle mounted on the tower, and a rotor defining a rotor axis extending along a vertical center plane, and is configured for harvesting wind energy by rotating blades about the rotor axis in a rotor rotational direction. The nacelle includes a rotor-support assembly that forms a load path from the rotor to the tower and is configured to receive rotor torque due to rotation of the rotor. In order to reduce the load of the tower and potentially provide a cheaper construction, the centre of gravity of the nacelle is offset from the centre plane in a direction relative to the direction of rotation of the rotor to counteract the rotor torque.

Description

Wind turbine with a nacelle having an offset centre of gravity

Technical Field

The present disclosure relates to a wind turbine (wind turbine) comprising a tower, a nacelle mounted on the tower and a rotor, the wind turbine being for harvesting wind energy by rotating the rotor about a rotor axis. The nacelle comprises: a rotor-support assembly (rotor-supporting assembly) that forms a load path from the rotor to the tower; and a main bearing attached to the rotor-support assembly and supporting rotation of the rotor relative to the rotor-support assembly.

Background

Wind turbines have increased in size in terms of nominal power output and in terms of the physical dimensions of the individual components of the wind turbine. Therefore, the size of the nacelle must also be increased to accommodate the required wind turbine components. Wind turbines are normally transported from one or more manufacturing locations of the individual components to the operating site where the wind turbine is erected by road, rail or ship or a combination thereof.

The increased size results in an increased load that has to be accommodated at multiple locations of the wind turbine. Within the nacelle, it is necessary to address the problem of torque-based loads (i.e., reaction loads generated by the rotor when power is applied in the powertrain (powertrain)). Significant reaction torque is applied from the driveline, particularly from the gearbox. In many designs, torque applied from a drive train (drivtrain) is brought to a frame carrying the gearbox via a torque arm. Typically, such forces are directed into the main frame where they are experienced as asymmetric loads. Therefore, the configuration and size of the rotor-support assembly must accommodate the torque.

Disclosure of Invention

It is an object of embodiments of the present disclosure to reduce the load, in particular the reaction load generated by the rotor when energy is applied in the drive train. In particular, it is an object of the present disclosure to reduce such asymmetric loading on the tower of a wind turbine and thus potentially reduce the weight, size and cost of the wind turbine (and in particular the tower portion thereof). This may potentially reduce transportation and handling costs without limiting the possible size of the wind turbine. It is another object of the present disclosure to provide a good balance between weight distribution and modularity.

In accordance with these and other objects, the present disclosure provides in a first aspect a wind turbine comprising a tower, a nacelle mounted on the tower, and a rotor defining a rotor axis extending along a vertical center plane, and configured for harvesting wind energy by rotating blades about the rotor axis in a direction of rotor rotation.

The nacelle includes a rotor-support assembly that includes a main frame, forms a load path from the rotor to the tower, and receives a degree of torque due to rotation of the rotor.

The centre of gravity (center of gravity, COG) of the nacelle is offset from the centre plane in a direction relative to the direction of rotation of the rotor to counteract the torque caused by the rotation of the rotor.

Since COG is offset such that it counteracts rotor torque, reducing the load caused by such asymmetric torque of the tower, and the tower junction between the tower and the nacelle (including the yaw assembly for yaw the nacelle) may optionally be smaller and cheaper.

The clockwise rotation of the rotor may be taken into account when looking at the rotor from the wind side. In this case the COG should be shifted to the left of the centre plane.

If the rotor rotates counter-clockwise (which is not common for wind turbines), COG should be shifted to the right of the centre plane.

The nacelle may be carried directly by the tower or indirectly by the tower via an intermediate tower structure. If the wind turbine is of the conventional horizontal axis type, the nacelle is typically carried by a yaw arrangement between the tower top and the nacelle. However, the present disclosure may also relate to multi-rotor wind turbines of the type in which more than one nacelle is carried by a beam structure, which in turn is carried by the tower, e.g. via a yaw arrangement between the tower and the beam structure.

The present disclosure may relate to upwind or downwind wind turbines.

The wind turbine may be a direct drive wind turbine, wherein the generator is typically placed outside the nacelle, or the generator of the wind turbine may be located in the main unit. The main unit supports the rotor via a rotor shaft.

The nacelle comprises a rotor-support assembly forming a load path from the rotor to the tower, e.g. via said intermediate tower structure and e.g. via said yaw means. The rotor-support assembly includes a main frame, for example in the form of a cast component, e.g., a component cast as a single piece.

The nacelle may additionally include various components for power production, hydraulic control, computers, and the like.

In addition to the main frame, the rotor-support assembly may also include bearing structures and other components that support the rotor in the wind turbine.

In facilitating development of wind turbine modularity, the nacelle may include: a main unit including a rotor-bearing assembly; and a first auxiliary unit attached to the main unit and accommodating an operating assembly for power conversion. With this arrangement, the benefit of the assembly is that the units can be produced in a manufacturing facility remote from the location where the wind turbine is erected, and that units that are only a subset of the entire nacelle can be transported more efficiently due to the smaller size and weight. In the place where the wind turbine is erected, the units may be assembled on the ground next to the tower, or on the tower.

The operating assembly may include a first transformer and a first transducer, and the distance from the first transducer to the center plane may be greater than the distance from the first transformer to the center plane.

The wind turbine may comprise a second auxiliary unit arranged such that the first auxiliary unit and the second auxiliary unit are located on opposite sides of the centre plane.

Providing a primary operating component of significant weight within the auxiliary unit provides the opportunity to significantly shift the resultant center of gravity (resultant center of gravity) in a manner that counteracts the reactive torque, as compared to conventional designs. The second auxiliary unit may include an operating assembly for power conversion, and the operating assembly of the first auxiliary unit and the operating assembly of the second auxiliary unit may be asymmetrically disposed about the center plane to provide for shifting of COG from the center plane.

The second auxiliary unit may include a second transformer and a second converter, and a distance from the first converter to the center plane may be greater than a distance from the second converter to the center plane. The transducer thus facilitates the displacement of COG from the central plane.

The nacelle may be rotatably connected to the wind turbine tower for rotation about a yaw axis extending along a vertical transverse plane perpendicular to the vertical center plane. In this embodiment, the transverse plane may be between the COG and the rotor, i.e. the COG is behind the vertical yaw axis when seen in the direction of the wind.

A first one of the operating components for power conversion, in particular the transformer, may be attached to the rotor-support assembly such that a first center of gravity of the first component (referred to herein as a first COG) is upwind relative to the COG. Upwind refers to being in the direction of the wind when the rotor is positioned in an operational position facing the wind.

A second one of the operating components for power conversion, in particular the converter, may be attached to the rotor-support assembly such that a second center of gravity of the second component (referred to herein as a second COG) is downwind relative to the COG. Downwind refers to being in a direction away from the wind when the rotor is positioned in an operational position facing the wind.

The rotor-support assembly may include a main frame and a main bearing housing attached to the main frame, the main bearing housing including a main bearing for rotational suspension of the rotor shaft relative to the main frame.

The main bearing housing may form part of a load path from the nacelle (and in particular from a first one of the operating assemblies) to the tower.

Displacement of COG away from the center plane may be caused by a load component (e.g., a first operating component for power conversion that is directly attached to the rotor-support assembly (e.g., directly attached to the main frame)).

Displacement of COG away from the central plane may be caused by load components (e.g., a second operating component for power conversion that is indirectly attached to the rotor-support assembly via, for example, an auxiliary unit and a main unit to the main frame).

Examples of primary and/or secondary units include units of any size and shape and configured to be assembled.

The auxiliary unit and/or the main unit may be formed to be of a size and/or external shape comparable to or equal to the size and shape of the freight container. Thus, each unit inherits the advantages of shipping containers in terms of handling, shipping, and storage. Freight containers can be handled anywhere in the world, for example, by ships, trains, trucks, etc., and are less costly than bulk transport.

The cost savings are even more pronounced when the primary unit and/or the secondary unit is a freight container. Freight containers are also known as intermodal containers, standard freight containers, box containers, sea containers, or ISO containers, and generally refer to containers that are used to store and move materials and products in a global containerized multi-modal system for intercontinental traffic. Freight containers may conform to the ISO standards of ISO 668:2013 for the size and structural specifications of series 1 freight containers.

The main unit and the auxiliary unit may be arranged side by side such that the auxiliary units are separated by a central plane in a direction away from the axis of rotation defined by the rotor-support assembly, instead of one after the other in the direction of the axis of rotation.

Each of the two auxiliary units may have half the size of one freight container following the ISO standard for the size and structural specifications of the series 1 freight container in ISO 668:2013 and be arranged such that both halves of the container may be assembled to form one container during transportation and may be split into two auxiliary units so as to be arranged on opposite sides of the main unit, for example. The containers may in particular be separated at joints extending in the longitudinal direction of the container, i.e. the longest dimension of the container.

Drawings

Hereinafter, various embodiments are described with reference to the accompanying drawings, in which:

FIG. 1a, FIG. 1b, and FIG. 1c illustrate a wind turbine with a nacelle mounted on a tower;

FIG. 2 illustrates a nacelle comprising a main unit and two auxiliary units;

FIG. 3 illustrates a perspective view of a nacelle;

FIG. 4 illustrates a portion of a rotor-support assembly, i.e., a main frame formed as a one-piece cast component;

FIG. 5 illustrates the rotor-support assembly as seen from one end of the rotor shaft;

fig. 6 to 7 illustrate different embodiments of the nacelle seen from above;

FIG. 8 illustrates details relating to the center of gravity of the different components;

fig. 9a, 9b, and 10 illustrate different joints between the operating assembly and the main frame;

FIG. 11 illustrates the primary and secondary units as separate units, an

Fig. 12 to 15 illustrate different joints between the main unit and the auxiliary unit.

Detailed Description

Since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this detailed description, the detailed description and specific examples, when given by way of illustration only, are given in the sense of indicating embodiments.

Fig. 1a and 1b illustrate a wind turbine 1 having a nacelle 2 mounted on a tower 3. A hub (hub) 4 carrying three rotor blades 5 forms the rotor and is carried by a rotor-bearing assembly in the nacelle 2. Typically, the rotor-support assembly includes a rotor shaft that connects the gear arrangement and the generator to a hub. However, gears are not always required, as the generator may be driven directly by the shaft. Fig. 1b illustrates a direct drive wind turbine with a generator 6 located outside the nacelle. The rotor-support assembly also includes a main frame, and a main bearing in a main bearing housing connected to the main frame.

As the rotor rotates, energy is dissipated in the drive train, especially as losses in the bearings and in the optional gearbox, and as energy transferred to the generator for conversion to electrical energy. In response to the dissipated energy, the rotor-support assembly must counteract the torque generated by the rotor that is powering the driveline. The reaction torque is experienced as a load directed into the tower from the rotor-support assembly.

The rotor rotates about a rotor axis 7 as defined herein. The vertical centre plane 8 of the longitudinal bisected wind nacelle (wind nacelle) 2 may be defined by a rotor axis extending in this plane. In order to direct the rotor towards the wind, the nacelle 2 is rotatable about a vertical yaw axis 9. A laterally extending transverse plane 10 may be defined, wherein the yaw axis extends within the transverse plane 10. The transverse plane 10 is perpendicular to the central plane. The yaw axis 9 extends both in the transverse plane 10 and in the centre plane 8.

Fig. 1c illustrates the centre plane and the transverse plane when the nacelle is seen from above. The tower is indicated by a circle 11 and has a radial dimension indicated by an arrow 12.

FIG. 2 illustrates a nacelle having a modular construction in which certain operational components are disposed within separate modules. More particularly, the nacelle comprises a main unit 20 and two auxiliary units 21, 22. The auxiliary units may be assembled separately, transported and mounted on the main unit. A cooling zone 23 is provided on top of the nacelle. The cooling zone is formed by a heat exchanger, which may form part of either the main unit and/or the auxiliary unit. The main unit 20 is mounted on the tower 3 via a rotor-bearing assembly and a yaw device (not shown). The yaw assembly allows the nacelle 2 to rotate about a yaw axis to direct the rotor into the wind.

Fig. 3 illustrates a perspective view of the nacelle 2 of fig. 2. In fig. 3, the outer wall of the nacelle 2 (for illustration purposes) is transparent, thereby exposing the interior portion of the nacelle 2 and the wind turbine components housed therein. The main unit 20 houses a rotor-bearing assembly that supports the rotor. The rotor-bearing assembly comprises, inter alia, a main frame and a main bearing 31 attached to the main frame for facilitating rotation of the rotor.

The disclosed wind turbine further comprises a gear arrangement 32 and a generator 33 arranged sequentially after the hub 4 in a direction defined by the rotational axis of the rotor. The components in the main unit mainly form part of the drive train. In an alternative embodiment, the generator is arranged outside the nacelle, as illustrated in fig. 1 b.

The auxiliary unit 22 houses the main components forming part of the power conversion system, more particularly the converter unit 34 and the transformer unit 35. In alternative embodiments, the auxiliary unit 22 houses, for example, an electrolytic cell stack or battery, or the like. The other auxiliary unit 21 is attached to the main unit on the opposite side of the centre plane and may contain similar operating components or other components (e.g. cranes, etc.). Hereinafter, such an assembly is referred to as an operation assembly.

The operating assembly is selected and placed such that the centre of gravity (COG) of the entire nacelle is offset from the centre plane in a direction relative to the direction of rotation of the rotor to counteract and optionally cancel the received torque.

Fig. 4 illustrates the main frame 40 formed as a one-piece cast assembly. The main frame further comprises an assembly structure 41 directly bolted to the casting assembly. The rotor-support assembly forms part of the nacelle and defines a load path from the rotor to the tower 3. In the embodiment of fig. 1 and 2, the rotor-support assembly is typically located in the main unit 20.

FIG. 5 illustrates the rotor-support assembly as seen against the wind from the rear of the nacelle toward the rotor face. The main bearing housing 50 is attached to the main frame 40. The main bearings allow the rotor to rotate relative to the main frame. Arrow 51 indicates the torque experienced by the rotor-support assembly.

Fig. 5 schematically shows that a load assembly 52 is provided on the assembly structure 41 for displacing the centre of gravity (COG) of the nacelle from the central plane 8, as illustrated by arrow 53. COG not in the center plane counteracts the experienced torque 51 due to rotation of the rotor. The counteracting torque provided by the displaced COG is illustrated by arrow 54. As discussed below, the load assembly is the primary operational assembly having a significant weight, such as a transformer. In the current latest generation designs of 10MW to 15MW ratings, the weight of the transformer is several tons, even up to 20 tons, so its positioning has a significant impact on the location of the COG.

The main bearing housing, when attached to the main frame, forms part of the load path from the load assembly 52 to the nacelle and to the tower.

Fig. 6 illustrates the nacelle 2 seen from above. The main unit 20 comprises a rotor-bearing assembly 40 and the auxiliary units 21, 22 each comprise a converter 34 and a transformer 35.

The main frame 40 includes a pair of assembly structures 41, 42 on opposite sides of the main frame 40. In this example, an operating component in the form of a transformer 35 is directly attached to the main frame. The main frame is fixed to the tower via a yaw assembly that allows rotation about a yaw axis. The main frame thus defines a load path extending directly from the operating assembly 35 through the main frame to the tower.

Other operating components 34 are indirectly attached to the rotor-support assembly via auxiliary units. The second operating component is attached to, for example, a floor or wall of the auxiliary unit, and the auxiliary unit is attached to the main unit. The auxiliary unit and the main unit thereby define a load path from the second operating component through the auxiliary unit to the rotor-support assembly and to the tower.

Fig. 6 illustrates that the operating component 35 (in this case the transformer 35) is located at the same distance from the centre plane 8, while the second operating component (in this case the transducer 34) is located at a different distance from the centre plane. This provides for displacing COG from the central plane 8 and thereby counteracting the experienced torque.

The optimal cancellation can be obtained by different combinations of positions. The transformer is typically heavier than the converter (although the converter also has a significant weight of a few tons, even up to 15 tons), and a slight displacement of the transformer 35 may have a greater impact than a considerable displacement of the converter 34.

Fig. 7 illustrates another example, in which only one auxiliary unit is placed on one side of the central plane 8, so that the entire mass of the auxiliary unit displaces the COG of the nacelle very significantly from the central plane and counteracts the torque experienced.

Fig. 8 illustrates a nacelle having the one-piece cast main frame of fig. 4. The first operating component 35 is directly attached to the rotor-support assembly and the center of gravity of the first operating component is labeled as the first COG. The first COG is positioned close to the transverse plane 10. By moving one of the first operating components, or by selecting a first operating component having a different weight, displacement of the COG away from the centre plane may be caused by a load component in the form of the first operating component being directly attached to the rotor-support assembly.

The second operating component 34 is placed on the floor of the auxiliary unit and is therefore only indirectly attached to the rotor-support assembly via the connection between the auxiliary unit and the main unit. The center of gravity of the second operational component is labeled as the second COG. The second COG is positioned further away from the transverse plane 10. By different positions of the second operating component, displacement of COG away from the centre plane may be caused by a load component indirectly attached to the rotor-support assembly.

The center of gravity of the auxiliary unit is marked AU-COG in the figure. The distance from the rotor plane 80 to the AU-COG is greater than the distance from the rotor plane to the first COG.

The first COG of the first assembly is upwind with respect to the COG and the second COG of the second assembly is downwind with respect to the COG.

Fig. 9a illustrates another assembled structure connecting the main frame to the operating assembly. In the illustrated embodiment, the assembly structure 90 connects the transformer 91 to the main frame. At the upper end of the assembly structure, a transverse pin 92 may be suspended from the main frame, while at the lower end of the assembly structure may be bolted to the main frame via holes 93. The assembly structure further comprises a lower support structure 94 on which the transformer may be carried on the floor of the nacelle, for example until final assembly and attachment to the main frame. In particular, the transformer may be placed on the floor of the auxiliary unit and bolted to the main frame once the auxiliary unit is attached to the main unit.

Fig. 9b illustrates an alternative assembly configuration in which both the upper and lower ends include pins 92, 95 to be suspended from the main frame.

Fig. 10 illustrates an alternative assembly structure in which both the upper and lower ends of one side include a bolt structure 100 to engage the main frame and both the upper and lower ends of the other side of the assembly structure form a hook structure 101 for hanging the operating assembly.

Fig. 11 schematically illustrates that the main unit and the auxiliary unit are separate units assembled before or after the nacelle is mounted on the tower. The reference numbers also relate to the wind turbines in fig. 3.

Fig. 12 to 15 illustrate four different embodiments of a unit fixing structure forming a joint (interface) between a main unit and an auxiliary unit. In each of these four drawings, the main unit 121 and the auxiliary unit 122 are connected by a cooperative structure forming a unit fixing structure, and are described in further detail below.

In fig. 12, the co-operating structure is constituted by a bracket (brecket) 123 through which the main unit and the auxiliary unit are connected by bolts.

In fig. 13, the cooperating structure is constituted by a lower bracket 123 similar to the bracket used in fig. 12. At the upper edge, the main unit and the auxiliary unit are assembled by a hook 131 pivotally connected to the main unit at a hinge point 132. The hooks may rotate as indicated by arrow 133 and, when in the illustrated position, engage the edge brackets 134 of the auxiliary unit. When the lower bracket 123 is removed and the hook 131 is rotated into the main unit, the auxiliary unit can be lowered to the ground.

The embodiment in fig. 14 may be comparable to the embodiment in fig. 13, but wherein the lower bracket is replaced with an upper bracket 141 and hooks are placed at the lower edge.

In fig. 15, the auxiliary unit is bolted to the main unit using a lower bracket and an upper bracket, and a slidable support 151 supports the lower surface of the auxiliary unit when the bolts are attached. If it is desired to lower the auxiliary unit to the ground (e.g. for replacement or maintenance of the operating assembly), the slidable support can be slid to the left and the auxiliary unit can be lowered, e.g. by using a crane built into the main unit.

In any of the embodiments shown in fig. 12-15, the bracket or hook directs the load from the auxiliary unit into a rigid portion of the main unit, for example into a load carrying post (e.g., a corner post of the main unit). Various structural features may connect brackets or hooks carrying auxiliary units directly to the main frame in the main unit, thereby establishing a load path to the tower. The auxiliary unit is thus indirectly connected to the tower via the main unit.

In addition to the hook and bracket unit securing structures illustrated in fig. 12-15, the assembly structure (e.g., as shown in fig. 4, 8, 9, and 10) also directly connects the operating assembly (e.g., transformer) to the main frame inside the main unit.

The main unit and the auxiliary unit may be connected after the operation assembly is placed in the auxiliary unit (e.g., after the transformer is placed in the auxiliary unit). The operating assembly may be placed, for example, on a floor of the auxiliary unit and it may be desirable that the weight of the operating assembly is carried mainly or entirely by the main frame in the main unit when the auxiliary unit is fixed to the main unit.

During assembly, load from the operating assembly is transferred from the auxiliary unit (e.g., from the floor of the auxiliary unit) to the main frame. Such load transfer may occur during or after the attachment of the auxiliary unit to the main unit.

In one process, the operating assembly is clamped by the assembled structure when the auxiliary unit is lowered to a position where it is secured to the main unit. When the assembled position of the auxiliary unit is reached, the load is transferred from the auxiliary unit to the main unit, in particular to the main frame in the main unit.

In an alternative procedure, the auxiliary unit is lowered to a position where it is fixed to the main unit. Subsequently, i.e. upon reaching the assembled position of the auxiliary unit, the load is transferred from the auxiliary unit to the main unit. This may for example comprise fixing the operating assembly to the assembled structure and optionally removing or lowering the support between the operating assembly and the floor of the auxiliary unit, allowing the entire load to be transferred to the main frame.

In another alternative procedure, the auxiliary unit is held at an angle inclined with respect to the horizontal plane while being lowered into position. When the first end of the auxiliary unit reaches the correct level, the first end is fixed to the main unit. The operating assembly is placed at the opposite second end of the auxiliary unit and at the point in time when the first end is being connected to the main unit, the operating assembly is still carried by the auxiliary unit, e.g. on the floor of the auxiliary unit. When the first end is secured, the second end is lowered and the operating assembly is clamped by the assembled structure. During continued lowering of the second end, the weight of the operating assembly is transferred from the auxiliary unit to the main frame, and finally the second end of the auxiliary unit is attached to the main unit.

In another alternative procedure, the auxiliary unit is lowered to a position where it is fixed to the main unit. During lowering of the auxiliary unit, the operating assembly is clamped by the assembly structure and at the same time the lifting force from the crane is adjusted to accommodate the varying balance when the operating assembly is clamped. When the assembled position of the auxiliary unit is reached, the load is transferred from the auxiliary unit to the main unit and remains balanced due to the dynamic adjustment of the lifting force (i.e. the adjustment is made while lowering the auxiliary unit).

Claims (16)

1. A wind turbine comprising a tower, a nacelle (2) mounted on the tower (3), and a rotor defining a rotor axis (7) extending along a vertical centre plane (8), and configured for harvesting wind energy by rotating blades (5) about the rotor axis in a rotor rotational direction, the nacelle comprising a rotor-support assembly comprising a main frame (40) forming a load path from the rotor to the tower and receiving a degree of torque due to rotation of the rotor, wherein a centre of gravity (COG) of the nacelle is offset from the centre plane (8) in a direction relative to the rotor rotational direction to counteract the torque due to rotation of the rotor.

2. The wind turbine of claim 1, wherein the rotor rotation direction is clockwise when viewed from a wind side of the rotor, and wherein the COG is offset to the left of the center plane.

3. Wind turbine according to any of the preceding claims, wherein one or more operating components (34, 35) forming part of the power conversion system are provided with a synthetic offset COG.

4. A wind turbine according to claim 3, wherein the operating component comprises a transformer and/or a converter.

5. A wind turbine according to any of the preceding claims, wherein the nacelle comprises: -a main unit (20) comprising the rotor-support assembly; and a first auxiliary unit (21) attached to the main unit and housing one or more operating components.

6. The wind turbine of claim 5, wherein the first auxiliary unit houses a first transformer and a first converter.

7. The wind turbine of claim 6, wherein a distance from the first transducer to the center plane is greater than a distance from the first transformer to the center plane.

8. Wind turbine according to claim 6, comprising a second auxiliary unit (22), the first and second auxiliary units being attached to the main unit on opposite sides of the central plane.

9. The wind turbine of claim 8, wherein the second auxiliary unit houses an operating assembly, and wherein the operating assembly of the first auxiliary unit and the operating assembly of the second auxiliary unit are asymmetrically disposed about the central plane.

10. Wind turbine according to claim 8 or 9, wherein the second auxiliary unit accommodates a second transformer and a second converter, and wherein the distance from the first converter to the central plane is larger than the distance from the second converter to the central plane.

11. Wind turbine according to any of the preceding claims, wherein the nacelle is rotatably connected to the wind turbine tower for rotation about a yaw axis (9) extending along a vertical transverse plane (10) perpendicular to the vertical central plane (8), and wherein the transverse plane is between the COG and the rotor.

12. Wind turbine according to any of claims 3-11, wherein a first one of the operating components for power conversion is attached to the rotor-support assembly such that a first centre of gravity (first COG) of the first component is upwind with respect to COG of the nacelle.

13. Wind turbine according to any of claims 3-12, wherein a second one of the operating components for power conversion is attached to the rotor-support assembly such that a second centre of gravity (second COG) of the second component is downwind with respect to the COG of the nacelle.

14. A wind turbine according to any of claims 3-13, wherein the rotor-support assembly comprises a main frame and a main bearing housing (50) attached to the main frame, the main bearing housing comprising a main bearing for rotational suspension of a rotor shaft relative to the main frame, and wherein the main bearing housing forms part of a load path from the operating assembly to the tower.

15. A wind turbine according to any of claims 3-14, wherein the operating component is directly attached to the rotor-support assembly.

16. A wind turbine according to any of claims 3-14, wherein the operating component is indirectly attached to the rotor-support assembly.